/**
 * Copyright (C) 2011 Angelo Zerr <angelo.zerr@gmail.com> and Pascal Leclercq <pascal.leclercq@gmail.com>
 *
 * All rights reserved.
 *
 * Permission is hereby granted, free  of charge, to any person obtaining
 * a  copy  of this  software  and  associated  documentation files  (the
 * "Software"), to  deal in  the Software without  restriction, including
 * without limitation  the rights to  use, copy, modify,  merge, publish,
 * distribute,  sublicense, and/or sell  copies of  the Software,  and to
 * permit persons to whom the Software  is furnished to do so, subject to
 * the following conditions:
 *
 * The  above  copyright  notice  and  this permission  notice  shall  be
 * included in all copies or substantial portions of the Software.
 *
 * THE  SOFTWARE IS  PROVIDED  "AS  IS", WITHOUT  WARRANTY  OF ANY  KIND,
 * EXPRESS OR  IMPLIED, INCLUDING  BUT NOT LIMITED  TO THE  WARRANTIES OF
 * MERCHANTABILITY,    FITNESS    FOR    A   PARTICULAR    PURPOSE    AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
 * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
 * OF CONTRACT, TORT OR OTHERWISE,  ARISING FROM, OUT OF OR IN CONNECTION
 * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 */
package fr.opensagres.eclipse.forms.internal;

import java.io.BufferedInputStream;
import java.io.BufferedReader;
import java.io.ByteArrayInputStream;
import java.io.CharArrayWriter;
import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.io.PrintWriter;
import java.io.Reader;
import java.io.StringWriter;
import java.io.Writer;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Iterator;
import java.util.List;

/**
 * General IO stream manipulation utilities.
 * <p>
 * This class provides static utility methods for input/output operations.
 * <ul>
 * <li>closeQuietly - these methods close a stream ignoring nulls and exceptions
 * <li>toXxx/read - these methods read data from a stream
 * <li>write - these methods write data to a stream
 * <li>copy - these methods copy all the data from one stream to another
 * <li>contentEquals - these methods compare the content of two streams
 * </ul>
 * <p>
 * The byte-to-char methods and char-to-byte methods involve a conversion step.
 * Two methods are provided in each case, one that uses the platform default
 * encoding and the other which allows you to specify an encoding. You are
 * encouraged to always specify an encoding because relying on the platform
 * default can lead to unexpected results, for example when moving from
 * development to production.
 * <p>
 * All the methods in this class that read a stream are buffered internally.
 * This means that there is no cause to use a <code>BufferedInputStream</code>
 * or <code>BufferedReader</code>. The default buffer size of 4K has been shown
 * to be efficient in tests.
 * <p>
 * Wherever possible, the methods in this class do <em>not</em> flush or close
 * the stream. This is to avoid making non-portable assumptions about the
 * streams' origin and further use. Thus the caller is still responsible for
 * closing streams after use.
 * <p>
 * Origin of code: Excalibur.
 * 
 * @author Peter Donald
 * @author Jeff Turner
 * @author Matthew Hawthorne
 * @author Stephen Colebourne
 * @author Gareth Davis
 * @author Ian Springer
 * @author Niall Pemberton
 * @author Sandy McArthur
 * @version $Id: IOUtils.java 481854 2006-12-03 18:30:07Z scolebourne $
 */
public class IOUtils {
	/**
	 * Logger for this class
	 */
	//private static final Logger logger = LogUtils.getLogger(IOUtils.class.getName());

	// NOTE: This class is focussed on InputStream, OutputStream, Reader and
	// Writer. Each method should take at least one of these as a parameter,
	// or return one of them.

	/**
	 * The Unix directory separator character.
	 */
	public static final char DIR_SEPARATOR_UNIX = '/';
	/**
	 * The Windows directory separator character.
	 */
	public static final char DIR_SEPARATOR_WINDOWS = '\\';
	/**
	 * The system directory separator character.
	 */
	public static final char DIR_SEPARATOR = File.separatorChar;
	/**
	 * The Unix line separator string.
	 */
	public static final String LINE_SEPARATOR_UNIX = "\n";
	/**
	 * The Windows line separator string.
	 */
	public static final String LINE_SEPARATOR_WINDOWS = "\r\n";
	/**
	 * The system line separator string.
	 */
	public static final String LINE_SEPARATOR;
	static {
		// avoid security issues
		StringWriter buf = new StringWriter(4);
		PrintWriter out = new PrintWriter(buf);
		out.println();
		LINE_SEPARATOR = buf.toString();
	}

	/**
	 * The default buffer size to use.
	 */
	private static final int DEFAULT_BUFFER_SIZE = 1024 * 4;

	/**
	 * Instances should NOT be constructed in standard programming.
	 */
	public IOUtils() {
		super();
	}

	// -----------------------------------------------------------------------
	/**
	 * Unconditionally close an <code>Reader</code>.
	 * <p>
	 * Equivalent to {@link Reader#close()}, except any exceptions will be
	 * ignored. This is typically used in finally blocks.
	 * 
	 * @param input
	 *            the Reader to close, may be null or already closed
	 */
	public static void closeQuietly(Reader input) {
		try {
			if (input != null) {
				input.close();
			}
		} catch (IOException ioe) {
			//logger.warning("Reader - exception ignored - exception: " + ioe); //$NON-NLS-1$

			// ignore
		}
	}

	/**
	 * Unconditionally close a <code>Writer</code>.
	 * <p>
	 * Equivalent to {@link Writer#close()}, except any exceptions will be
	 * ignored. This is typically used in finally blocks.
	 * 
	 * @param output
	 *            the Writer to close, may be null or already closed
	 */
	public static void closeQuietly(Writer output) {
		try {
			if (output != null) {
				output.close();
			}
		} catch (IOException ioe) {
			//logger.warning("Writer - exception ignored - exception: " + ioe); //$NON-NLS-1$

			// ignore
		}
	}

	/**
	 * Unconditionally close an <code>InputStream</code>.
	 * <p>
	 * Equivalent to {@link InputStream#close()}, except any exceptions will be
	 * ignored. This is typically used in finally blocks.
	 * 
	 * @param input
	 *            the InputStream to close, may be null or already closed
	 */
	public static void closeQuietly(InputStream input) {
		try {
			if (input != null) {
				input.close();
			}
		} catch (IOException ioe) {
			//logger.warning("InputStream - exception ignored - exception: " + ioe); //$NON-NLS-1$

			// ignore
		}
	}

	/**
	 * Unconditionally close an <code>OutputStream</code>.
	 * <p>
	 * Equivalent to {@link OutputStream#close()}, except any exceptions will be
	 * ignored. This is typically used in finally blocks.
	 * 
	 * @param output
	 *            the OutputStream to close, may be null or already closed
	 */
	public static void closeQuietly(OutputStream output) {
		try {
			if (output != null) {
				output.close();
			}
		} catch (IOException ioe) {
			//logger.warning("OutputStream - exception ignored - exception: " + ioe); //$NON-NLS-1$

			// ignore
		}
	}

	// read toByteArray
	// -----------------------------------------------------------------------
	/**
	 * Get the contents of an <code>InputStream</code> as a <code>byte[]</code>.
	 * <p>
	 * This method buffers the input internally, so there is no need to use a
	 * <code>BufferedInputStream</code>.
	 * 
	 * @param input
	 *            the <code>InputStream</code> to read from
	 * @return the requested byte array
	 * @throws NullPointerException
	 *             if the input is null
	 * @throws IOException
	 *             if an I/O error occurs
	 */
	public static byte[] toByteArray(InputStream input) throws IOException {
		ByteArrayOutputStream output = new ByteArrayOutputStream();
		copy(input, output);
		return output.toByteArray();
	}

	/**
	 * Get the contents of a <code>Reader</code> as a <code>byte[]</code> using
	 * the default character encoding of the platform.
	 * <p>
	 * This method buffers the input internally, so there is no need to use a
	 * <code>BufferedReader</code>.
	 * 
	 * @param input
	 *            the <code>Reader</code> to read from
	 * @return the requested byte array
	 * @throws NullPointerException
	 *             if the input is null
	 * @throws IOException
	 *             if an I/O error occurs
	 */
	public static byte[] toByteArray(Reader input) throws IOException {
		ByteArrayOutputStream output = new ByteArrayOutputStream();
		copy(input, output);
		return output.toByteArray();
	}

	/**
	 * Get the contents of a <code>Reader</code> as a <code>byte[]</code> using
	 * the specified character encoding.
	 * <p>
	 * Character encoding names can be found at <a
	 * href="http://www.iana.org/assignments/character-sets">IANA</a>.
	 * <p>
	 * This method buffers the input internally, so there is no need to use a
	 * <code>BufferedReader</code>.
	 * 
	 * @param input
	 *            the <code>Reader</code> to read from
	 * @param encoding
	 *            the encoding to use, null means platform default
	 * @return the requested byte array
	 * @throws NullPointerException
	 *             if the input is null
	 * @throws IOException
	 *             if an I/O error occurs
	 * @since Commons IO 1.1
	 */
	public static byte[] toByteArray(Reader input, String encoding)
			throws IOException {
		ByteArrayOutputStream output = new ByteArrayOutputStream();
		copy(input, output, encoding);
		return output.toByteArray();
	}

	/**
	 * Get the contents of a <code>String</code> as a <code>byte[]</code> using
	 * the default character encoding of the platform.
	 * <p>
	 * This is the same as {@link String#getBytes()}.
	 * 
	 * @param input
	 *            the <code>String</code> to convert
	 * @return the requested byte array
	 * @throws NullPointerException
	 *             if the input is null
	 * @throws IOException
	 *             if an I/O error occurs (never occurs)
	 * @deprecated Use {@link String#getBytes()}
	 */
	public static byte[] toByteArray(String input) throws IOException {
		return input.getBytes();
	}

	// read char[]
	// -----------------------------------------------------------------------
	/**
	 * Get the contents of an <code>InputStream</code> as a character array
	 * using the default character encoding of the platform.
	 * <p>
	 * This method buffers the input internally, so there is no need to use a
	 * <code>BufferedInputStream</code>.
	 * 
	 * @param is
	 *            the <code>InputStream</code> to read from
	 * @return the requested character array
	 * @throws NullPointerException
	 *             if the input is null
	 * @throws IOException
	 *             if an I/O error occurs
	 * @since Commons IO 1.1
	 */
	public static char[] toCharArray(InputStream is) throws IOException {
		CharArrayWriter output = new CharArrayWriter();
		copy(is, output);
		return output.toCharArray();
	}

	/**
	 * Get the contents of an <code>InputStream</code> as a character array
	 * using the specified character encoding.
	 * <p>
	 * Character encoding names can be found at <a
	 * href="http://www.iana.org/assignments/character-sets">IANA</a>.
	 * <p>
	 * This method buffers the input internally, so there is no need to use a
	 * <code>BufferedInputStream</code>.
	 * 
	 * @param is
	 *            the <code>InputStream</code> to read from
	 * @param encoding
	 *            the encoding to use, null means platform default
	 * @return the requested character array
	 * @throws NullPointerException
	 *             if the input is null
	 * @throws IOException
	 *             if an I/O error occurs
	 * @since Commons IO 1.1
	 */
	public static char[] toCharArray(InputStream is, String encoding)
			throws IOException {
		CharArrayWriter output = new CharArrayWriter();
		copy(is, output, encoding);
		return output.toCharArray();
	}

	/**
	 * Get the contents of a <code>Reader</code> as a character array.
	 * <p>
	 * This method buffers the input internally, so there is no need to use a
	 * <code>BufferedReader</code>.
	 * 
	 * @param input
	 *            the <code>Reader</code> to read from
	 * @return the requested character array
	 * @throws NullPointerException
	 *             if the input is null
	 * @throws IOException
	 *             if an I/O error occurs
	 * @since Commons IO 1.1
	 */
	public static char[] toCharArray(Reader input) throws IOException {
		CharArrayWriter sw = new CharArrayWriter();
		copy(input, sw);
		return sw.toCharArray();
	}

	// read toString
	// -----------------------------------------------------------------------
	/**
	 * Get the contents of an <code>InputStream</code> as a String using the
	 * default character encoding of the platform.
	 * <p>
	 * This method buffers the input internally, so there is no need to use a
	 * <code>BufferedInputStream</code>.
	 * 
	 * @param input
	 *            the <code>InputStream</code> to read from
	 * @return the requested String
	 * @throws NullPointerException
	 *             if the input is null
	 * @throws IOException
	 *             if an I/O error occurs
	 */
	public static String toString(InputStream input) throws IOException {
		StringWriter sw = new StringWriter();
		copy(input, sw);
		return sw.toString();
	}

	/**
	 * Get the contents of an <code>InputStream</code> as a String using the
	 * specified character encoding.
	 * <p>
	 * Character encoding names can be found at <a
	 * href="http://www.iana.org/assignments/character-sets">IANA</a>.
	 * <p>
	 * This method buffers the input internally, so there is no need to use a
	 * <code>BufferedInputStream</code>.
	 * 
	 * @param input
	 *            the <code>InputStream</code> to read from
	 * @param encoding
	 *            the encoding to use, null means platform default
	 * @return the requested String
	 * @throws NullPointerException
	 *             if the input is null
	 * @throws IOException
	 *             if an I/O error occurs
	 */
	public static String toString(InputStream input, String encoding)
			throws IOException {
		StringWriter sw = new StringWriter();
		copy(input, sw, encoding);
		return sw.toString();
	}

	/**
	 * Get the contents of a <code>Reader</code> as a String.
	 * <p>
	 * This method buffers the input internally, so there is no need to use a
	 * <code>BufferedReader</code>.
	 * 
	 * @param input
	 *            the <code>Reader</code> to read from
	 * @return the requested String
	 * @throws NullPointerException
	 *             if the input is null
	 * @throws IOException
	 *             if an I/O error occurs
	 */
	public static String toString(Reader input) throws IOException {
		StringWriter sw = new StringWriter();
		copy(input, sw);
		return sw.toString();
	}

	/**
	 * Get the contents of a <code>byte[]</code> as a String using the default
	 * character encoding of the platform.
	 * 
	 * @param input
	 *            the byte array to read from
	 * @return the requested String
	 * @throws NullPointerException
	 *             if the input is null
	 * @throws IOException
	 *             if an I/O error occurs (never occurs)
	 * @deprecated Use {@link String#String(byte[])}
	 */
	public static String toString(byte[] input) throws IOException {
		return new String(input);
	}

	/**
	 * Get the contents of a <code>byte[]</code> as a String using the specified
	 * character encoding.
	 * <p>
	 * Character encoding names can be found at <a
	 * href="http://www.iana.org/assignments/character-sets">IANA</a>.
	 * 
	 * @param input
	 *            the byte array to read from
	 * @param encoding
	 *            the encoding to use, null means platform default
	 * @return the requested String
	 * @throws NullPointerException
	 *             if the input is null
	 * @throws IOException
	 *             if an I/O error occurs (never occurs)
	 * @deprecated Use {@link String#String(byte[],String)}
	 */
	public static String toString(byte[] input, String encoding)
			throws IOException {
		if (encoding == null) {
			return new String(input);
		} else {
			return new String(input, encoding);
		}
	}

	// readLines
	// -----------------------------------------------------------------------
	/**
	 * Get the contents of an <code>InputStream</code> as a list of Strings, one
	 * entry per line, using the default character encoding of the platform.
	 * <p>
	 * This method buffers the input internally, so there is no need to use a
	 * <code>BufferedInputStream</code>.
	 * 
	 * @param input
	 *            the <code>InputStream</code> to read from, not null
	 * @return the list of Strings, never null
	 * @throws NullPointerException
	 *             if the input is null
	 * @throws IOException
	 *             if an I/O error occurs
	 * @since Commons IO 1.1
	 */
	public static List<String> readLines(InputStream input) throws IOException {
		InputStreamReader reader = new InputStreamReader(input);
		return readLines(reader);
	}

	/**
	 * Get the contents of an <code>InputStream</code> as a list of Strings, one
	 * entry per line, using the specified character encoding.
	 * <p>
	 * Character encoding names can be found at <a
	 * href="http://www.iana.org/assignments/character-sets">IANA</a>.
	 * <p>
	 * This method buffers the input internally, so there is no need to use a
	 * <code>BufferedInputStream</code>.
	 * 
	 * @param input
	 *            the <code>InputStream</code> to read from, not null
	 * @param encoding
	 *            the encoding to use, null means platform default
	 * @return the list of Strings, never null
	 * @throws NullPointerException
	 *             if the input is null
	 * @throws IOException
	 *             if an I/O error occurs
	 * @since Commons IO 1.1
	 */
	public static List<String> readLines(InputStream input, String encoding)
			throws IOException {
		if (encoding == null) {
			return readLines(input);
		} else {
			InputStreamReader reader = new InputStreamReader(input, encoding);
			return readLines(reader);
		}
	}

	/**
	 * Get the contents of a <code>Reader</code> as a list of Strings, one entry
	 * per line.
	 * <p>
	 * This method buffers the input internally, so there is no need to use a
	 * <code>BufferedReader</code>.
	 * 
	 * @param input
	 *            the <code>Reader</code> to read from, not null
	 * @return the list of Strings, never null
	 * @throws NullPointerException
	 *             if the input is null
	 * @throws IOException
	 *             if an I/O error occurs
	 * @since Commons IO 1.1
	 */
	public static List<String> readLines(Reader input) throws IOException {
		BufferedReader reader = new BufferedReader(input);
		List<String> list = new ArrayList<String>();
		String line = reader.readLine();
		while (line != null) {
			list.add(line);
			line = reader.readLine();
		}
		return list;
	}

	// lineIterator
	// -----------------------------------------------------------------------
	/**
	 * Return an Iterator for the lines in a <code>Reader</code>.
	 * <p>
	 * <code>LineIterator</code> holds a reference to the open
	 * <code>Reader</code> specified here. When you have finished with the
	 * iterator you should close the reader to free internal resources. This can
	 * be done by closing the reader directly, or by calling
	 * {@link LineIterator#close()} or
	 * {@link LineIterator#closeQuietly(LineIterator)}.
	 * <p>
	 * The recommended usage pattern is:
	 * 
	 * <pre>
	 * try {
	 * 	LineIterator it = IOUtils.lineIterator(reader);
	 * 	while (it.hasNext()) {
	 * 		String line = it.nextLine();
	 * 		// / do something with line
	 * 	}
	 * } finally {
	 * 	IOUtils.closeQuietly(reader);
	 * }
	 * </pre>
	 * 
	 * @param reader
	 *            the <code>Reader</code> to read from, not null
	 * @return an Iterator of the lines in the reader, never null
	 * @throws IllegalArgumentException
	 *             if the reader is null
	 * @since Commons IO 1.2
	 */
	public static LineIterator lineIterator(Reader reader) {
		return new LineIterator(reader);
	}

	/**
	 * Return an Iterator for the lines in an <code>InputStream</code>, using
	 * the character encoding specified (or default encoding if null).
	 * <p>
	 * <code>LineIterator</code> holds a reference to the open
	 * <code>InputStream</code> specified here. When you have finished with the
	 * iterator you should close the stream to free internal resources. This can
	 * be done by closing the stream directly, or by calling
	 * {@link LineIterator#close()} or
	 * {@link LineIterator#closeQuietly(LineIterator)}.
	 * <p>
	 * The recommended usage pattern is:
	 * 
	 * <pre>
	 * try {
	 * 	LineIterator it = IOUtils.lineIterator(stream, &quot;UTF-8&quot;);
	 * 	while (it.hasNext()) {
	 * 		String line = it.nextLine();
	 * 		// / do something with line
	 * 	}
	 * } finally {
	 * 	IOUtils.closeQuietly(stream);
	 * }
	 * </pre>
	 * 
	 * @param input
	 *            the <code>InputStream</code> to read from, not null
	 * @param encoding
	 *            the encoding to use, null means platform default
	 * @return an Iterator of the lines in the reader, never null
	 * @throws IllegalArgumentException
	 *             if the input is null
	 * @throws IOException
	 *             if an I/O error occurs, such as if the encoding is invalid
	 * @since Commons IO 1.2
	 */
	public static LineIterator lineIterator(InputStream input, String encoding)
			throws IOException {
		Reader reader = null;
		if (encoding == null) {
			reader = new InputStreamReader(input);
		} else {
			reader = new InputStreamReader(input, encoding);
		}
		return new LineIterator(reader);
	}

	// -----------------------------------------------------------------------
	/**
	 * Convert the specified string to an input stream, encoded as bytes using
	 * the default character encoding of the platform.
	 * 
	 * @param input
	 *            the string to convert
	 * @return an input stream
	 * @since Commons IO 1.1
	 */
	public static InputStream toInputStream(String input) {
		byte[] bytes = input.getBytes();
		return new ByteArrayInputStream(bytes);
	}

	/**
	 * Convert the specified string to an input stream, encoded as bytes using
	 * the specified character encoding.
	 * <p>
	 * Character encoding names can be found at <a
	 * href="http://www.iana.org/assignments/character-sets">IANA</a>.
	 * 
	 * @param input
	 *            the string to convert
	 * @param encoding
	 *            the encoding to use, null means platform default
	 * @throws IOException
	 *             if the encoding is invalid
	 * @return an input stream
	 * @since Commons IO 1.1
	 */
	public static InputStream toInputStream(String input, String encoding)
			throws IOException {
		byte[] bytes = encoding != null ? input.getBytes(encoding) : input
				.getBytes();
		return new ByteArrayInputStream(bytes);
	}

	// write byte[]
	// -----------------------------------------------------------------------
	/**
	 * Writes bytes from a <code>byte[]</code> to an <code>OutputStream</code>.
	 * 
	 * @param data
	 *            the byte array to write, do not modify during output, null
	 *            ignored
	 * @param output
	 *            the <code>OutputStream</code> to write to
	 * @throws NullPointerException
	 *             if output is null
	 * @throws IOException
	 *             if an I/O error occurs
	 * @since Commons IO 1.1
	 */
	public static void write(byte[] data, OutputStream output)
			throws IOException {
		if (data != null) {
			output.write(data);
		}
	}

	/**
	 * Writes bytes from a <code>byte[]</code> to chars on a <code>Writer</code>
	 * using the default character encoding of the platform.
	 * <p>
	 * This method uses {@link String#String(byte[])}.
	 * 
	 * @param data
	 *            the byte array to write, do not modify during output, null
	 *            ignored
	 * @param output
	 *            the <code>Writer</code> to write to
	 * @throws NullPointerException
	 *             if output is null
	 * @throws IOException
	 *             if an I/O error occurs
	 * @since Commons IO 1.1
	 */
	public static void write(byte[] data, Writer output) throws IOException {
		if (data != null) {
			output.write(new String(data));
		}
	}

	/**
	 * Writes bytes from a <code>byte[]</code> to chars on a <code>Writer</code>
	 * using the specified character encoding.
	 * <p>
	 * Character encoding names can be found at <a
	 * href="http://www.iana.org/assignments/character-sets">IANA</a>.
	 * <p>
	 * This method uses {@link String#String(byte[], String)}.
	 * 
	 * @param data
	 *            the byte array to write, do not modify during output, null
	 *            ignored
	 * @param output
	 *            the <code>Writer</code> to write to
	 * @param encoding
	 *            the encoding to use, null means platform default
	 * @throws NullPointerException
	 *             if output is null
	 * @throws IOException
	 *             if an I/O error occurs
	 * @since Commons IO 1.1
	 */
	public static void write(byte[] data, Writer output, String encoding)
			throws IOException {
		if (data != null) {
			if (encoding == null) {
				write(data, output);
			} else {
				output.write(new String(data, encoding));
			}
		}
	}

	// write char[]
	// -----------------------------------------------------------------------
	/**
	 * Writes chars from a <code>char[]</code> to a <code>Writer</code> using
	 * the default character encoding of the platform.
	 * 
	 * @param data
	 *            the char array to write, do not modify during output, null
	 *            ignored
	 * @param output
	 *            the <code>Writer</code> to write to
	 * @throws NullPointerException
	 *             if output is null
	 * @throws IOException
	 *             if an I/O error occurs
	 * @since Commons IO 1.1
	 */
	public static void write(char[] data, Writer output) throws IOException {
		if (data != null) {
			output.write(data);
		}
	}

	/**
	 * Writes chars from a <code>char[]</code> to bytes on an
	 * <code>OutputStream</code>.
	 * <p>
	 * This method uses {@link String#String(char[])} and
	 * {@link String#getBytes()}.
	 * 
	 * @param data
	 *            the char array to write, do not modify during output, null
	 *            ignored
	 * @param output
	 *            the <code>OutputStream</code> to write to
	 * @throws NullPointerException
	 *             if output is null
	 * @throws IOException
	 *             if an I/O error occurs
	 * @since Commons IO 1.1
	 */
	public static void write(char[] data, OutputStream output)
			throws IOException {
		if (data != null) {
			output.write(new String(data).getBytes());
		}
	}

	/**
	 * Writes chars from a <code>char[]</code> to bytes on an
	 * <code>OutputStream</code> using the specified character encoding.
	 * <p>
	 * Character encoding names can be found at <a
	 * href="http://www.iana.org/assignments/character-sets">IANA</a>.
	 * <p>
	 * This method uses {@link String#String(char[])} and
	 * {@link String#getBytes(String)}.
	 * 
	 * @param data
	 *            the char array to write, do not modify during output, null
	 *            ignored
	 * @param output
	 *            the <code>OutputStream</code> to write to
	 * @param encoding
	 *            the encoding to use, null means platform default
	 * @throws NullPointerException
	 *             if output is null
	 * @throws IOException
	 *             if an I/O error occurs
	 * @since Commons IO 1.1
	 */
	public static void write(char[] data, OutputStream output, String encoding)
			throws IOException {
		if (data != null) {
			if (encoding == null) {
				write(data, output);
			} else {
				output.write(new String(data).getBytes(encoding));
			}
		}
	}

	// write String
	// -----------------------------------------------------------------------
	/**
	 * Writes chars from a <code>String</code> to a <code>Writer</code>.
	 * 
	 * @param data
	 *            the <code>String</code> to write, null ignored
	 * @param output
	 *            the <code>Writer</code> to write to
	 * @throws NullPointerException
	 *             if output is null
	 * @throws IOException
	 *             if an I/O error occurs
	 * @since Commons IO 1.1
	 */
	public static void write(String data, Writer output) throws IOException {
		if (data != null) {
			output.write(data);
		}
	}

	/**
	 * Writes chars from a <code>String</code> to bytes on an
	 * <code>OutputStream</code> using the default character encoding of the
	 * platform.
	 * <p>
	 * This method uses {@link String#getBytes()}.
	 * 
	 * @param data
	 *            the <code>String</code> to write, null ignored
	 * @param output
	 *            the <code>OutputStream</code> to write to
	 * @throws NullPointerException
	 *             if output is null
	 * @throws IOException
	 *             if an I/O error occurs
	 * @since Commons IO 1.1
	 */
	public static void write(String data, OutputStream output)
			throws IOException {
		if (data != null) {
			output.write(data.getBytes());
		}
	}

	/**
	 * Writes chars from a <code>String</code> to bytes on an
	 * <code>OutputStream</code> using the specified character encoding.
	 * <p>
	 * Character encoding names can be found at <a
	 * href="http://www.iana.org/assignments/character-sets">IANA</a>.
	 * <p>
	 * This method uses {@link String#getBytes(String)}.
	 * 
	 * @param data
	 *            the <code>String</code> to write, null ignored
	 * @param output
	 *            the <code>OutputStream</code> to write to
	 * @param encoding
	 *            the encoding to use, null means platform default
	 * @throws NullPointerException
	 *             if output is null
	 * @throws IOException
	 *             if an I/O error occurs
	 * @since Commons IO 1.1
	 */
	public static void write(String data, OutputStream output, String encoding)
			throws IOException {
		if (data != null) {
			if (encoding == null) {
				write(data, output);
			} else {
				output.write(data.getBytes(encoding));
			}
		}
	}

	// write StringBuffer
	// -----------------------------------------------------------------------
	/**
	 * Writes chars from a <code>StringBuffer</code> to a <code>Writer</code>.
	 * 
	 * @param data
	 *            the <code>StringBuffer</code> to write, null ignored
	 * @param output
	 *            the <code>Writer</code> to write to
	 * @throws NullPointerException
	 *             if output is null
	 * @throws IOException
	 *             if an I/O error occurs
	 * @since Commons IO 1.1
	 */
	public static void write(StringBuffer data, Writer output)
			throws IOException {
		if (data != null) {
			output.write(data.toString());
		}
	}

	/**
	 * Writes chars from a <code>StringBuffer</code> to bytes on an
	 * <code>OutputStream</code> using the default character encoding of the
	 * platform.
	 * <p>
	 * This method uses {@link String#getBytes()}.
	 * 
	 * @param data
	 *            the <code>StringBuffer</code> to write, null ignored
	 * @param output
	 *            the <code>OutputStream</code> to write to
	 * @throws NullPointerException
	 *             if output is null
	 * @throws IOException
	 *             if an I/O error occurs
	 * @since Commons IO 1.1
	 */
	public static void write(StringBuffer data, OutputStream output)
			throws IOException {
		if (data != null) {
			output.write(data.toString().getBytes());
		}
	}

	/**
	 * Writes chars from a <code>StringBuffer</code> to bytes on an
	 * <code>OutputStream</code> using the specified character encoding.
	 * <p>
	 * Character encoding names can be found at <a
	 * href="http://www.iana.org/assignments/character-sets">IANA</a>.
	 * <p>
	 * This method uses {@link String#getBytes(String)}.
	 * 
	 * @param data
	 *            the <code>StringBuffer</code> to write, null ignored
	 * @param output
	 *            the <code>OutputStream</code> to write to
	 * @param encoding
	 *            the encoding to use, null means platform default
	 * @throws NullPointerException
	 *             if output is null
	 * @throws IOException
	 *             if an I/O error occurs
	 * @since Commons IO 1.1
	 */
	public static void write(StringBuffer data, OutputStream output,
			String encoding) throws IOException {
		if (data != null) {
			if (encoding == null) {
				write(data, output);
			} else {
				output.write(data.toString().getBytes(encoding));
			}
		}
	}

	// writeLines
	// -----------------------------------------------------------------------
	/**
	 * Writes the <code>toString()</code> value of each item in a collection to
	 * an <code>OutputStream</code> line by line, using the default character
	 * encoding of the platform and the specified line ending.
	 * 
	 * @param lines
	 *            the lines to write, null entries produce blank lines
	 * @param lineEnding
	 *            the line separator to use, null is system default
	 * @param output
	 *            the <code>OutputStream</code> to write to, not null, not
	 *            closed
	 * @throws NullPointerException
	 *             if the output is null
	 * @throws IOException
	 *             if an I/O error occurs
	 * @since Commons IO 1.1
	 */
	public static void writeLines(Collection<String> lines, String lineEnding,
			OutputStream output) throws IOException {
		if (lines == null) {
			return;
		}
		if (lineEnding == null) {
			lineEnding = LINE_SEPARATOR;
		}
		for (Iterator<String> it = lines.iterator(); it.hasNext();) {
			String line = it.next();
			if (line != null) {
				output.write(line.getBytes());
			}
			output.write(lineEnding.getBytes());
		}
	}

	/**
	 * Writes the <code>toString()</code> value of each item in a collection to
	 * an <code>OutputStream</code> line by line, using the specified character
	 * encoding and the specified line ending.
	 * <p>
	 * Character encoding names can be found at <a
	 * href="http://www.iana.org/assignments/character-sets">IANA</a>.
	 * 
	 * @param lines
	 *            the lines to write, null entries produce blank lines
	 * @param lineEnding
	 *            the line separator to use, null is system default
	 * @param output
	 *            the <code>OutputStream</code> to write to, not null, not
	 *            closed
	 * @param encoding
	 *            the encoding to use, null means platform default
	 * @throws NullPointerException
	 *             if the output is null
	 * @throws IOException
	 *             if an I/O error occurs
	 * @since Commons IO 1.1
	 */
	public static void writeLines(Collection<String> lines, String lineEnding,
			OutputStream output, String encoding) throws IOException {
		if (encoding == null) {
			writeLines(lines, lineEnding, output);
		} else {
			if (lines == null) {
				return;
			}
			if (lineEnding == null) {
				lineEnding = LINE_SEPARATOR;
			}
			for (Iterator<String> it = lines.iterator(); it.hasNext();) {
				Object line = it.next();
				if (line != null) {
					output.write(line.toString().getBytes(encoding));
				}
				output.write(lineEnding.getBytes(encoding));
			}
		}
	}

	/**
	 * Writes the <code>toString()</code> value of each item in a collection to
	 * a <code>Writer</code> line by line, using the specified line ending.
	 * 
	 * @param lines
	 *            the lines to write, null entries produce blank lines
	 * @param lineEnding
	 *            the line separator to use, null is system default
	 * @param writer
	 *            the <code>Writer</code> to write to, not null, not closed
	 * @throws NullPointerException
	 *             if the input is null
	 * @throws IOException
	 *             if an I/O error occurs
	 * @since Commons IO 1.1
	 */
	public static void writeLines(Collection<String> lines, String lineEnding,
			Writer writer) throws IOException {
		if (lines == null) {
			return;
		}
		if (lineEnding == null) {
			lineEnding = LINE_SEPARATOR;
		}
		for (Iterator<String> it = lines.iterator(); it.hasNext();) {
			String line = it.next();
			if (line != null) {
				writer.write(line);
			}
			writer.write(lineEnding);
		}
	}

	// copy from InputStream
	// -----------------------------------------------------------------------
	/**
	 * Copy bytes from an <code>InputStream</code> to an
	 * <code>OutputStream</code>.
	 * <p>
	 * This method buffers the input internally, so there is no need to use a
	 * <code>BufferedInputStream</code>.
	 * <p>
	 * Large streams (over 2GB) will return a bytes copied value of
	 * <code>-1</code> after the copy has completed since the correct number of
	 * bytes cannot be returned as an int. For large streams use the
	 * <code>copyLarge(InputStream, OutputStream)</code> method.
	 * 
	 * @param input
	 *            the <code>InputStream</code> to read from
	 * @param output
	 *            the <code>OutputStream</code> to write to
	 * @return the number of bytes copied
	 * @throws NullPointerException
	 *             if the input or output is null
	 * @throws IOException
	 *             if an I/O error occurs
	 * @throws ArithmeticException
	 *             if the byte count is too large
	 * @since Commons IO 1.1
	 */
	public static int copy(InputStream input, OutputStream output)
			throws IOException {
		long count = copyLarge(input, output);
		if (count > Integer.MAX_VALUE) {
			return -1;
		}
		return (int) count;
	}

	/**
	 * Copy bytes from a large (over 2GB) <code>InputStream</code> to an
	 * <code>OutputStream</code>.
	 * <p>
	 * This method buffers the input internally, so there is no need to use a
	 * <code>BufferedInputStream</code>.
	 * 
	 * @param input
	 *            the <code>InputStream</code> to read from
	 * @param output
	 *            the <code>OutputStream</code> to write to
	 * @return the number of bytes copied
	 * @throws NullPointerException
	 *             if the input or output is null
	 * @throws IOException
	 *             if an I/O error occurs
	 * @since Commons IO 1.3
	 */
	public static long copyLarge(InputStream input, OutputStream output)
			throws IOException {
		byte[] buffer = new byte[DEFAULT_BUFFER_SIZE];
		long count = 0;
		int n = 0;
		while (-1 != (n = input.read(buffer))) {
			output.write(buffer, 0, n);
			count += n;
		}
		return count;
	}

	/**
	 * Copy bytes from an <code>InputStream</code> to chars on a
	 * <code>Writer</code> using the default character encoding of the platform.
	 * <p>
	 * This method buffers the input internally, so there is no need to use a
	 * <code>BufferedInputStream</code>.
	 * <p>
	 * This method uses {@link InputStreamReader}.
	 * 
	 * @param input
	 *            the <code>InputStream</code> to read from
	 * @param output
	 *            the <code>Writer</code> to write to
	 * @throws NullPointerException
	 *             if the input or output is null
	 * @throws IOException
	 *             if an I/O error occurs
	 * @since Commons IO 1.1
	 */
	public static void copy(InputStream input, Writer output)
			throws IOException {
		InputStreamReader in = new InputStreamReader(input);
		copy(in, output);
	}

	/**
	 * Copy bytes from an <code>InputStream</code> to chars on a
	 * <code>Writer</code> using the specified character encoding.
	 * <p>
	 * This method buffers the input internally, so there is no need to use a
	 * <code>BufferedInputStream</code>.
	 * <p>
	 * Character encoding names can be found at <a
	 * href="http://www.iana.org/assignments/character-sets">IANA</a>.
	 * <p>
	 * This method uses {@link InputStreamReader}.
	 * 
	 * @param input
	 *            the <code>InputStream</code> to read from
	 * @param output
	 *            the <code>Writer</code> to write to
	 * @param encoding
	 *            the encoding to use, null means platform default
	 * @throws NullPointerException
	 *             if the input or output is null
	 * @throws IOException
	 *             if an I/O error occurs
	 * @since Commons IO 1.1
	 */
	public static void copy(InputStream input, Writer output, String encoding)
			throws IOException {
		if (encoding == null) {
			copy(input, output);
		} else {
			InputStreamReader in = new InputStreamReader(input, encoding);
			copy(in, output);
		}
	}

	// copy from Reader
	// -----------------------------------------------------------------------
	/**
	 * Copy chars from a <code>Reader</code> to a <code>Writer</code>.
	 * <p>
	 * This method buffers the input internally, so there is no need to use a
	 * <code>BufferedReader</code>.
	 * <p>
	 * Large streams (over 2GB) will return a chars copied value of
	 * <code>-1</code> after the copy has completed since the correct number of
	 * chars cannot be returned as an int. For large streams use the
	 * <code>copyLarge(Reader, Writer)</code> method.
	 * 
	 * @param input
	 *            the <code>Reader</code> to read from
	 * @param output
	 *            the <code>Writer</code> to write to
	 * @return the number of characters copied
	 * @throws NullPointerException
	 *             if the input or output is null
	 * @throws IOException
	 *             if an I/O error occurs
	 * @throws ArithmeticException
	 *             if the character count is too large
	 * @since Commons IO 1.1
	 */
	public static int copy(Reader input, Writer output) throws IOException {
		long count = copyLarge(input, output);
		if (count > Integer.MAX_VALUE) {
			return -1;
		}
		return (int) count;
	}

	/**
	 * Copy chars from a large (over 2GB) <code>Reader</code> to a
	 * <code>Writer</code>.
	 * <p>
	 * This method buffers the input internally, so there is no need to use a
	 * <code>BufferedReader</code>.
	 * 
	 * @param input
	 *            the <code>Reader</code> to read from
	 * @param output
	 *            the <code>Writer</code> to write to
	 * @return the number of characters copied
	 * @throws NullPointerException
	 *             if the input or output is null
	 * @throws IOException
	 *             if an I/O error occurs
	 * @since Commons IO 1.3
	 */
	public static long copyLarge(Reader input, Writer output)
			throws IOException {
		char[] buffer = new char[DEFAULT_BUFFER_SIZE];
		long count = 0;
		int n = 0;
		while (-1 != (n = input.read(buffer))) {
			output.write(buffer, 0, n);
			count += n;
		}
		return count;
	}

	/**
	 * Copy chars from a <code>Reader</code> to bytes on an
	 * <code>OutputStream</code> using the default character encoding of the
	 * platform, and calling flush.
	 * <p>
	 * This method buffers the input internally, so there is no need to use a
	 * <code>BufferedReader</code>.
	 * <p>
	 * Due to the implementation of OutputStreamWriter, this method performs a
	 * flush.
	 * <p>
	 * This method uses {@link OutputStreamWriter}.
	 * 
	 * @param input
	 *            the <code>Reader</code> to read from
	 * @param output
	 *            the <code>OutputStream</code> to write to
	 * @throws NullPointerException
	 *             if the input or output is null
	 * @throws IOException
	 *             if an I/O error occurs
	 * @since Commons IO 1.1
	 */
	public static void copy(Reader input, OutputStream output)
			throws IOException {
		OutputStreamWriter out = new OutputStreamWriter(output);
		copy(input, out);
		// XXX Unless anyone is planning on rewriting OutputStreamWriter, we
		// have to flush here.
		out.flush();
	}

	/**
	 * Copy chars from a <code>Reader</code> to bytes on an
	 * <code>OutputStream</code> using the specified character encoding, and
	 * calling flush.
	 * <p>
	 * This method buffers the input internally, so there is no need to use a
	 * <code>BufferedReader</code>.
	 * <p>
	 * Character encoding names can be found at <a
	 * href="http://www.iana.org/assignments/character-sets">IANA</a>.
	 * <p>
	 * Due to the implementation of OutputStreamWriter, this method performs a
	 * flush.
	 * <p>
	 * This method uses {@link OutputStreamWriter}.
	 * 
	 * @param input
	 *            the <code>Reader</code> to read from
	 * @param output
	 *            the <code>OutputStream</code> to write to
	 * @param encoding
	 *            the encoding to use, null means platform default
	 * @throws NullPointerException
	 *             if the input or output is null
	 * @throws IOException
	 *             if an I/O error occurs
	 * @since Commons IO 1.1
	 */
	public static void copy(Reader input, OutputStream output, String encoding)
			throws IOException {
		if (encoding == null) {
			copy(input, output);
		} else {
			OutputStreamWriter out = new OutputStreamWriter(output, encoding);
			copy(input, out);
			// XXX Unless anyone is planning on rewriting OutputStreamWriter,
			// we have to flush here.
			out.flush();
		}
	}

	// content equals
	// -----------------------------------------------------------------------
	/**
	 * Compare the contents of two Streams to determine if they are equal or
	 * not.
	 * <p>
	 * This method buffers the input internally using
	 * <code>BufferedInputStream</code> if they are not already buffered.
	 * 
	 * @param input1
	 *            the first stream
	 * @param input2
	 *            the second stream
	 * @return true if the content of the streams are equal or they both don't
	 *         exist, false otherwise
	 * @throws NullPointerException
	 *             if either input is null
	 * @throws IOException
	 *             if an I/O error occurs
	 */
	public static boolean contentEquals(InputStream input1, InputStream input2)
			throws IOException {
		if (!(input1 instanceof BufferedInputStream)) {
			input1 = new BufferedInputStream(input1);
		}
		if (!(input2 instanceof BufferedInputStream)) {
			input2 = new BufferedInputStream(input2);
		}

		int ch = input1.read();
		while (-1 != ch) {
			int ch2 = input2.read();
			if (ch != ch2) {
				return false;
			}
			ch = input1.read();
		}

		int ch2 = input2.read();
		return (ch2 == -1);
	}

	/**
	 * Compare the contents of two Readers to determine if they are equal or
	 * not.
	 * <p>
	 * This method buffers the input internally using
	 * <code>BufferedReader</code> if they are not already buffered.
	 * 
	 * @param input1
	 *            the first reader
	 * @param input2
	 *            the second reader
	 * @return true if the content of the readers are equal or they both don't
	 *         exist, false otherwise
	 * @throws NullPointerException
	 *             if either input is null
	 * @throws IOException
	 *             if an I/O error occurs
	 * @since Commons IO 1.1
	 */
	public static boolean contentEquals(Reader input1, Reader input2)
			throws IOException {
		if (!(input1 instanceof BufferedReader)) {
			input1 = new BufferedReader(input1);
		}
		if (!(input2 instanceof BufferedReader)) {
			input2 = new BufferedReader(input2);
		}

		int ch = input1.read();
		while (-1 != ch) {
			int ch2 = input2.read();
			if (ch != ch2) {
				return false;
			}
			ch = input1.read();
		}

		int ch2 = input2.read();
		return (ch2 == -1);
	}

}
